$(function(){
	$.extend(true, $.validator, {
        defaults: {
            onfocusout: function (element, event) {
            	
            	if (element.value == "") {//此部分为修改的代码
                    if ($(element).rules().required == true) { 
                        $(element).valid();
                    }
                } else {
	                if (!this.checkable(element) && (element.name in this.submitted || !this.optional(element))) {
	                    this.element(element);
	                }
                }
            	
            }
        }
	});
});